Hydrotech 2510 Valve Chemical Free Iron Filter Operation Manual - Manual (Page 10)

10
Section 5: Backwashing Instructions
To Calculate Backwash Frequency - Normal Applications
Backwash frequency, for households with average water use, can be determined using the following guide. The guide
cannot be used if the filtered water supplies a swimming pool, geothermal pump, outside spigots or other high water
demand devices or activities. If your application includes an of the forgoing refer to the paragraph on Special
Applications.
1. Locate the box intersected by the number of people in
your family and the parts per million (PPM) of iron in your
water (if your PPM is between two numbers on the guide,
use the higher number).
2. The number in the box represents how many times your
filter has to backwash in a twelve day schedule.
Example: You have four in the family and 8 PPM of iron. Refer to the guide and locate the box intersected by four in the
family and 8 PPM of iron. The figure supplied is 2. This means your filter control should be programmed to backwash
twice in twelve days — that is every sixth day. If the figure had been 3 it would mean 3 backwashes in twelve days or
every fourth day.
To Calculate Backwash Frequency - Special Applications
To ensure adequate reserve capacity and prevent loss of water pressure between backwashes the figure of 15,000, not
the full 30,000 ppm capacity, is used to calculate backwash frequency. Determine your backwash frequency as follows:
1. Estimate daily iron removal requirements using the following calculation:
No. of people in Family
X 75 gallons of water per person
+ No. of gallons of water for special use
= No. of gallons of water required per day
X Iron concentration (PPM)
= Daily iron removal requirements (PPM)
2. Establish backwash frequency using daily iron removal requirements to complete the following calculation:
15,000 iron removal capacity (PPM)
÷ Daily iron removal requirements (PPM)
= No. of backwashes required in 12 day schedule.
Example: You have four in the family 8 PPM of iron and a swimming pool requiring 46 gallons of water per day.
4 People in the family
X 75 Gallons of water per person
300 Gallons of water for family
+ 46 Gallons of water for the pool
346 Gallons of water required per day
X 8 Iron concentration (PPM)
2,768 Daily iron removal requirements
15,000 Iron removal capacity (PPM)
÷ 2,768
Daily iron removal requirements (PPM)
5.4 Backwash frequency (days)
The calculation indicates the need to backwash every 5.4 days. The control can only be programmed to backwash at
intervals of two, three, four, six and twelve days. The control would be programmed to the closest more frequent setting
i.e. every four days.
Iron Content (PPM)
2 4 6 8 10 12 14 16 18 20
1 1 1 1 1 1 1 1 1 1 1
2 1 1 1 1 1 2 2 2 2 2
3 1 1 1 2 2 2 3 3 3 3
4 1 1 2 2 2 3 3 4 4 4
5 1 1 2 2 3 3 4 4 6 6
6 1 2 2 3 3 4 6 6 6 6
People
in
Family